Commonly assigned U.S. Pat. No. 5,191,265 entitled "Wall Mounted Programmable Modular Control System" (the 265 patent) describes a fully modular, wall mountable control system for use with various loads, and particularly lighting loads. The entirety of the 265 patent is incorporated herein by reference. The control system described in the 265 patent employs a master unit and at least one slave unit to independently control loads, such as lighting zones. In the context of lighting control, a zone is defined as one or more light sources that are commonly controlled, i.e., by the master or by one of the slaves, but a zone can include any type of load that can be electrically controlled. Each master and slave contains control electronics for controlling one zone, although the 265 patent also describes a slave that has a pair of control units for controlling two zones. As used herein, and unless a contrary intent is indicated elsewhere, the term "control unit" means those control electronics and associated actuators (pushbuttons, sliders, switches and the like) present in a wall mountable control panel needed to control a zone, including programming of a zone. Further, as used herein, and unless a contrary intent is indicated elsewhere, the term "control panel" means the wall mounted housing containing all of the control units.
According to the system described in the 265 patent, each control unit has an intensity raise/lower actuator, and associated electronics, for programming/controlling a single zone, and a display for providing an indication of the intensity level of a single zone. In other words, each control unit is capable of programming and controlling only one zone. Thus, increasing the number of zones to be controlled requires increasing the number of control units by the addition of modular slave units.
A commercial embodiment of the control system described in the 265 patent has been offered for sale and sold by the assignee hereof, for more than one year before the filing date of this application, under the trademark GRAFIK Eye.RTM.. However, unlike the system described in the 265 patent, the GRAFIK Eye.RTM. system is not modular. Rather, the control units of the GRAFIK Eye.RTM. are hard-wired together within the control panel. As in the case of the 265 patent, each control unit in the GRAFIK Eye.RTM. control panel has an intensity raise/lower actuator, and associated electronics, for programming/controlling a single zone, and a display for providing an indication of the programmed intensity level, or actual intensity level, for a single zone. Each control unit is capable of programming and controlling only one zone. Because the control units are not modular and are hard-wired together, the control panels are manufactured in selected sizes to control only pre-selected numbers of zones. Thus, plural control panels may be needed to control more zones than can be controlled with the largest single control panel sold by the manufacturer. In addition, any increase in the number of zones desired to be controlled after original installation requires purchase of a new control panel with the extra control units.
One commercial version of the GRAFIK Eye.RTM. system, known as the GRAFIK Eye.RTM. Model 4100, differs from the system primarily described in the 265 patent in that the dimming electronics used to respond to the commands of the GRAFIK Eye.RTM. Model 4100 control panel and to directly control the zones are remotely located, and communicate with the GRAFIK Eye.RTM. control panel over a low voltage, class 2, four wire link. However, the 265 patent does describe the use of remote dimming circuits at column 15, lines 10 et seq. The remote dimming electronics adjust the delivered power level to the light sources of each zone in response to digital commands received over the four wire link. Dimming electronics for use with the GRAFIK Eye.RTM. Model 4100 control panel are commercially available from the assignee hereof and are sold under the mark GRAFIK Eye.RTM. GP Dimming Panel. Commonly assigned U.S. Pat. No. 5,530,322 entitled "Multi-Zone Lighting Control System" (the 322 patent), the entirety of which is incorporated herein by reference, also describes the structure and operation of a remote dimming panel that may be employed with a programmable wall mountable control panel in the manner suggested at column 15, lines 10 et seq. of the 265 patent. The GRAFIK Eye.RTM. GP Dimming Panel is a commercial embodiment of the system described in the 322 patent, and the 322 patent generally describes the structure and operation thereof. The GRAFIK Eye.RTM. GP Dimming Control Panel is capable of receiving commands from up to eight GRAFIK Eye.RTM. control panels to control up to 64 zones. Each GRAFIK Eye.RTM. control panel has its own unique address which is incorporated into the digital commands.
The GRAFIK Eye.RTM. system, including the GRAFIK Eye.RTM. Model 4100 control panel and the GRAFIK Eye.RTM. GP Dimming Panel are described in a brochure published by Lutron Electronics Co., Inc. as part number P/N 360-449 entitled "GRAFIK Eye.RTM. Multi-Scene Preset Dimming Controls" (1996), the entirety of which is also incorporated herein by reference.
Each of the systems described above requires the use of a great amount of hardware, and the use of a great amount of wall space for the control units, to control a large number of zones. Thus, a system with a large number of zones can be unsightly and costly. The present invention overcomes this problem.